The 802.3 based Ethernet defined by the Institute of Electrical and Electronics Engineers (IEEE) has been used as a service interface in various scenarios. An Ethernet rate gradually increases with rapid development of communications technologies such that the 10 megabits per second (Mbit/s) Ethernet, the Fast Ethernet (FE), and the 1 gigabit Ethernet (GE) gradually evolve to the current 100 GE and the 400 GE to be defined by the IEEE. Rapid popularization of the Ethernet propels evolution of the Ethernet from a pure interface technology to a network technology similar to a transport network.
Currently, the Optical Internetworking Forum (OIF) is discussing expansion of a conventional Ethernet application scenario in order to support functions such as a subsrate, channelization, and inverse multiplexing for an Ethernet service. Such an Ethernet technology is referred to as a Flexible Ethernet (FlexE). For example, in a subsrate application scenario of an Ethernet service, a 250 gigabits per second (Gbit/s) Ethernet service (Media Access Control (MAC) bitstream) can be transmitted using three existing 100GE Physical Medium Dependent (PMD) sublayers. In an inverse multiplexing application scenario of an Ethernet service, a 200 Gbit/s Ethernet service can be transmitted using two existing 100 GE PMDs. In a channelization application scenario of an Ethernet service, similar to a multiplexing function of an optical transport network (OTN), multiple low-rate Ethernet services can be multiplexed to a high-rate FlexE.
As a mainstream transport network technology, the OTN technology can implement flexible scheduling and management of a large-capacity service by virtue of abundant Operation, Administration and Maintenance (OAM), a high Tandem Connection Monitoring (TCM) capability, and an out-of-band Forward Error Correction (FEC) capability. An OTN interface is widely used in an existing network. In addition, technologies such as a Synchronous Digital Hierarchy (SDH) interface and a Constant bit rate (CBR) interface in another form widely exist in the existing network.
In the other approaches, a FlexE shim layer is defined in the FlexE such that a service layer of multiple Ethernet services aggregates traffic of a client layer. However, the foregoing method needs to be based on a MAC frame of the Ethernet, and an idle code block defined in the Ethernet needs to be deleted to perform rate adaptation. Neither a MAC frame nor an idle frame is defined in a CBR service, such as an OTN service or an SDH service. Therefore, mapping to the FlexE cannot be implemented, and rate adaptation cannot be performed.